At present, various types of chipsets are required to set a sleep mode for each circuit of the wafer in response to energy saving standards. However, a large inrush current occurs when the circuit of the wafer is woken up from the sleep mode and the circuit of the chipset can only operate stably after a period of time.
There are two kinds of wake-up methods for circuit power switches in various regions of the chipset. One of the methods is that, the power switches of the circuits are turned on sequentially. The other is that, all of the power switches of the circuit are turned on at the same time. The former method takes a long time for all circuits to wake up, and the latter method has a very large inrush current.
Therefore, providing a power-on method that can reduce the inrush current is an important issue in the industry.